The requirements to sell here:

If you are level 6 then you can open a selling thread here.

If you reach level 8 you get sticky thread in the sellers section.

Other requirements: None

You can bypass this rule by becoming VIP, you must purchase something in the official selling thread in order to become VIP.

If you are caught scamming, not refunding or replacing dead accounts/invites then you will be banned.
The minimum warranty you offer must be 1 year.